Battery pack assembly using an ultraviolet responsive adhesive

ABSTRACT

The disclosed technology relates to a battery pack assembly that includes multiple battery cells. In some aspects, each cell is bonded to a first surface of a first liner (e.g., a cosmetic liner) via a first adhesive. The first adhesive is configured to provide a first adhesive force between each of the battery cells and the first surface before exposure to ultraviolet (UV) light and a second adhesive force after exposure to UV light, and wherein the second adhesive force is less than the first adhesive force. A battery pallet and method of manufacturing are also provided.

PRIORITY

This application is a continuation of U.S. patent application Ser. No.15/833,266, entitled “BATTERY PACK ASSEMBLY USING AN ULTRAVIOLETRESPONSIVE ADHESIVE,” filed on Dec. 6, 2017, which claims the benefitunder 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No.62/563,292, entitled “BATTERY PACK ASSEMBLY USING AN ULTRAVIOLETRESPONSIVE ADHESIVE”, filed on Sep. 26, 2017, each which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to battery packs, and moreparticularly, to the use of an ultraviolet responsive liner configuredto facilitate battery pack transport and insertion into abattery-powered device.

BACKGROUND

Battery cells are used to provide power to a wide variety of portableelectronic devices, including laptop computers, tablet computers, smartphones, personal digital assistants (PDAs), digital music players,watches, and wearable devices. A commonly used type of battery is alithium battery that can include a lithium-ion or a lithium-polymerbattery. In some applications, where greater charge storage is desired,multiple battery cells can be coupled to form battery packs of increasedstorage capacity.

Multi-cell battery packs are commonly placed in an interior volume of anassociated battery powered device. In some arrangements, individualcells may physically separated and stored in different locations, forexample, in an interior chassis of the battery-powered device.

SUMMARY

The disclosed embodiments provide a battery pack having multiple batterycells that are bonded to a first surface of a first liner via a firstadhesive. The first adhesive is configured to provide a first adhesiveforce between each of the battery cells and the first surface beforeexposure to ultraviolet (UV) light, and a second adhesive force afterexposure to UV light, wherein the second adhesive force is less than thefirst adhesive force. In some aspects, the battery pack further includesmultiple pads that are bonded to a second surface of the first liner viaa second adhesive, wherein the second adhesive is configured to providea third adhesive force between each of the pads and the second surfaceof the first liner, and wherein the third adhesive force is less thanthe first adhesive force.

In some aspects, the disclosed technology provides a battery pallet thatincludes multiple of battery packs. Each of the battery packs includemultiple battery cells that are bonded to a first surface of a firstliner via a first adhesive. The first adhesive can be configured toprovide a first adhesive force between each of the battery cells and thefirst surface before exposure of the first surface to ultraviolet (UV)light and a second adhesive force after exposure to UV light.

In yet another aspect, the disclosed technology provides a method ofmanufacturing a battery pack. The method can include steps for bondingmultiple battery cells to a first surface of a first liner using a firstadhesive, and wherein the first adhesive provides a first adhesive forcebetween each of the battery cells and the first surface before exposureto ultraviolet (UV) light, and a second adhesive force after exposure toUV light.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments disclosed herein may be better understood by referringto the following description in conjunction with the accompanyingdrawings in which like reference numerals indicate identical orfunctionally similar elements. Understanding that these drawings depictonly exemplary embodiments of the disclosure and are not therefore to beconsidered to be limiting of its scope, the principles herein aredescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 illustrates a side view of an example battery pack, according tosome aspects of the subject technology.

FIG. 2A illustrates a top-perspective view of a chassis for abattery-powered device, including multiple battery bays that areconfigured to receive battery cells, according to some aspects of thetechnology.

FIG. 2B illustrates a top-perspective view of a battery pack that hasbeen placed in a chassis of a battery-powered device, according to someaspects of the technology.

FIG. 2C illustrates a top-perspective view of a battery pack that isbeen placed in a chassis of a battery-powered device after removal of atop carrier liner and a cosmetic liner, according to some aspects of thetechnology.

FIG. 3 illustrates an example process for manufacturing a battery pack,according to some aspects of the technology;

FIG. 4 illustrates a portable electronic device, in accordance with someaspects of the subject technology.

DETAILED DESCRIPTION

Various embodiments of the disclosure are discussed in detail below.While specific implementations are discussed, it should be understoodthat this is done for illustration purposes only. A person skilled inthe relevant art will recognize that other components and configurationsmay be used without parting from the spirit and scope of the technology.

Battery-powered electronic devices can contain battery packs made up ofmultiple, electrically coupled, battery cells. In some configurations,space and/or layout constraints can be alleviated by placement of thecells at disjoint locations in the device chassis. In some approaches,battery cells are bonded to an interior surface of the chassis atdifferent locations in battery bays, which are configured to accommodatecells of a particular dimension. Depending on the device assembly,battery bays can be irregularly spaced and/or configured to hold cellsof different dimensions.

The irregularity of bay placement and cell dimensions can complicate theprocess of battery pack insertion into the chassis. For example, tomaintain a tight fit, care must be taken to ensure that the correctcells are placed within the correct bays. The insertion process can befurther complicated where adhesive bonding between the cells and chassesoccurs upon insertion of a particular cell into a corresponding batterybay, making cell removal and re-insertion (e.g., to fix incorrectplacements) more difficult.

Aspects of the technology address the foregoing problems by providingbattery packs in which the cells are bonded to a set of liners atpre-configured spacing intervals, which correspond with spacingintervals of corresponding battery bays in a receiving chassis. Sucharrangements facilitate the transportation and insertion of cells into adevice at proper bay spacing intervals. In some aspects, the batterypack can include liners that are configured for convenient removal afterbattery pack insertion is complete.

In some battery pack assemblies of the disclosed technology, eachbattery cell is bonded to a first liner (e.g., a cosmetic liner), usinga first adhesive that is reactive to light in the ultraviolent range,i.e., a UV adhesive or UV reactive adhesive. The first liner is, inturn, bonded to a set of pads coupled with a second liner (e.g., acarrier liner) using a second adhesive of a weaker bond strength. Usingthe two-liner configuration, once battery cells are inserted into theircorresponding battery bays, the second liner can be easily removed toexpose the first liner. Subsequent exposure of the first liner to UVlight weakens the first adhesive, facilitating final removal for thefirst liner from the battery cells.

Weakening of the first adhesive bond strength can depend on a variety offactors, including: the first adhesive composition, light exposurewavelength, light exposure power, and light exposure time. In someaspects, the first adhesive may be reactive to light of a wavelength inthe 300-400 nm range. In other aspects, the first adhesive may bereactive to light of a wavelength in the 350-375 nm range. By way offurther example, the first adhesive may be reactive to light of awavelength of approximately 365 nm. Additionally, in some aspects,exposure powers can vary from between 500-1000 mJ. For example, lightexposure power may be between 700-800 mJ. In one embodiment, theexposure power may be approximately 720 mJ. Exposure times may also varyfrom between 2-10 seconds. In one embodiment, the first adhesive isexposed to UV light for 4 seconds.

Additional details regarding the battery back configuration, as well asa process for assembling a battery pack of the subject technology, areprovided with respect to FIGS. 1-5, discussed below.

FIG. 1 illustrates a side view of an example battery pack 100. Batterypack 100 includes multiple battery cells 112, as well as multipleliners, i.e., a first liner 108, and a second liner 102. Second liner102 further includes pads 104, that are positioned opposite from batterycells 112, with respect to first liner 108. Specifically, in theorientation illustrated in FIG. 1, battery cells 112 are bonded to afirst surface 108A of first liner 108; pads 104 are positioned on a topside of first liner 108, i.e., on second surface 108B, opposite frombattery cells 112. Although the example of FIG. 1 illustrates batterypack 100 as having three battery cells (e.g., 112A, 112B, and 112C), itis understood that battery pack 100 may have a greater (or fewer) numberof cells, without departing from the scope of the technology.

Additionally, individual battery cells 112A, 112B, and 112C areillustrated as having a substantially similar height, each of the cellsmay have a different height, length and/or width. In some aspects,differences in height between cells may correspond with differences inthe thickness of a corresponding pad 104. That is, a cell of a shorterrelative height may be positioned opposite from a pad of a longerrelative height, with respect to first liner 108. For example, thethickness of each individual pad can correspond with a thickness of theassociated battery cell such that thicker battery cells are paired withthinner pads, and thinner (or shorter) battery cells are paired withthicker (or taller) pads. In some aspects, a total height for a givenbattery cell/pad pair is equal across all cell/pad pairings in thebattery pack.

In battery pack 100, battery cells 112 are bonded to a first surface108A, of first liner 108, e.g., by a first adhesive 106. First adhesive106 is a UV reactive adhesive that provides a first adhesive forcebefore exposure to UV light, and a second adhesive force after exposureto UV light. In some implementations, the second adhesive force is lessthan the first adhesive force, such that the adhesive bond of firstadhesive 106 is weakened through UV light exposure. As such, UV lightexposure can be used to aid removal of the first liner 108 from the packassembly, as discussed in further detail below.

In the assembled configuration of battery pack 100, first liner 108 isblocked from UV light exposure through shielding provided by pads 104,which are coupled to second surface 108B of first liner 108, e.g., bysecond adhesive 110. Incident light can also be shielded from reachingfirst liner 108 through occlusion provided by second liner 102. That is,pads 104 and/or second liner 102 can block light, and particularly UVlight, from reaching first liner 108, for example, to prevent a decreasein the adhesive strength of first adhesive 106.

In operation, battery pack 100 can be conveniently placed into a chassisof a receiving device, such that each of battery cells 112 are fittedinto a respectively receiving battery bay (not illustrated). The secondliner 102 and first liner 108 can then be stripped away, leaving batterycells 112 in their respective battery bay positions. By way of example,second liner 102 may be stripped from battery pack 100, breaking theadhesive bond between pads 104 and second surface 108B provided bysecond adhesive 110, e.g., which may comprise a medium tack adhesive. Insuch implementations, a third adhesive force provided by second adhesive110, is less than the first adhesive force between first liner 108 andbattery cells 112 provided by first adhesive 106. As such, removal ofsecond liner 102 leaves a second surface 108B of first liner 108 exposedto incident light.

Subsequently, UV light can be provided onto first liner 108 to weakenthe bonding force of first adhesive 106, i.e., to decrease the adhesivebond between battery cells 112 and second surface 108A from a firstadhesive force (relatively strong) to a second adhesive force(relatively weak). In some aspects, first liner 108 is constructed of amaterial configured to pass UV light, for example, so that incidentlight on second surface 108B can reach first adhesive 106. That is,first liner 108 may be constructed of a transparent or translucentmaterial.

By reducing the adhesive strength of first adhesive 106 (e.g., throughUV light exposure), first liner 108 can be easily stripped away frombattery cells 112, leaving the cells in their respective locationswithin a receiving chassis (not illustrated). By way of example, priorto UV light exposure, the first adhesive can provide a bond strength(first adhesive force) between the battery cells and a first surface ofthe first liner that is between 50-100 gf (gram force). In anotherexample, the first adhesive can provide a first adhesive force betweenthe battery cells and the first liner that is between 65-80 gf. In yetanother example, the first adhesive can provide a first adhesive forceof about 70 gf.

The first adhesive can be configured to significantly decrease in bondstrength upon exposure to UV light, for example, that is in the range ofabout 355-370 nm. Once exposed, the first adhesive provides a secondadhesive force that is significantly reduced from the first adhesiveforce. By way of example, the second adhesive force may be in the rangeof 5-15 gf. In another example, the second adhesive force may be in therange of 7-12 gf. In yet another example, the second adhesive force maybe about 10 gf.

FIG. 2A illustrates a top-perspective view of an example chassis 200 fora battery-powered device, including multiple battery bays 201 configuredto receive respective battery cells. Battery bays 201 can be regularlyor irregularly spaced, and may be of different dimensions, for example,to accommodate different battery cell dimensions, depending on thedesired implementation. Battery bays 201 can also have the same (ordifferent) depth dimensions, e.g., to accommodate respective batterycells of a similar (or different) heights. Although chassis 200 depictedin FIG. 2A contains four battery bays 201, it is understood that chassis200 may have a greater (or fewer) number of bays, without departing fromthe scope of the technology.

FIG. 2B illustrates a top-perspective view of a battery pack 202 thathas been placed in chassis 200. Battery pack 202 is shown from atop-perspective of a carrier liner e.g., second liner 102, discussedabove with respect to FIG. 1. In the example of FIG. 2B, the carrierliner is illustrated as being semi-transparent, for example, toillustrate the underlying pads disposed above respective cells 112, inbattery bays 201. However, it is understood that the carrier liner canbe made of an opaque material to block light, depending on the desiredimplementation.

As further illustrated in FIG. 2B, battery pack 202 includes a tab 204disposed on one edge of the carrier liner. Tab 204 can be configured tofacilitate the convenient removal of the carrier liner. Carrier liner,e.g., a second liner 102, can be stripped away using tab 204, exposing acosmetic liner, e.g., a first liner 108, disposed over cells 112 (alsoreferring to FIG. 1). As discussed above, removal of the carrier linercan be accomplished without disturbing battery cells 212, because anadhesive, e.g., a second adhesive 110, that bonds the carrier liner/padassembly to the cosmetic liner (first liner 108), has a lower adhesiveforce (e.g., a third adhesive force) than is provided by the UVadhesive, e.g., a first adhesive, between the battery cells and pads,prior to UV exposure.

FIG. 2C illustrates a top-perspective view of battery pack 202 that isbeen placed in a chassis after removal of a carrier liner (e.g., asecond liner) and cosmetic liner (e.g., a first liner). As illustrated,battery cells 212 (e.g., individual cells 212A, 212B, 212C, and 212D)have different dimensions and relative spacing; however, it isunderstood that cell dimensions and spacing could be uniform, withoutdeparting from the scope of the technology.

FIG. 3 illustrates an example process 300 for manufacturing a batterypack. Process 300 begins with step 302 in which one or more batterycells are bonded to a first surface of a first liner using a firstadhesive. As discussed above, the first liner may be a transparent ortranslucent cosmetic liner configured to provide physical continuitybetween multiple battery cells, for example, to facilitate shipping andeasy insertion into a device chassis.

The first adhesive can be a reactive adhesive configured to decrease inbond strength upon exposure to certain wavelengths of light, such as UVlight. By way of example, prior to UV light exposure, the first adhesivecan provide a bond strength (first adhesive force) between the batterycells and a first surface of the first liner that is between 50-100 gf(gram force). In another example, the first adhesive can provide a firstadhesive force between the battery cells and the first liner that isbetween 65-80 gf. In yet another example, the first adhesive can providea first adhesive force of about 70 gf.

The first adhesive can be configured to significantly decrease in bondstrength upon exposure to UV light, for example, that is in the range ofabout 355-370 nm. Once exposed, the first adhesive provides a secondadhesive force that is significantly reduced from the first adhesiveforce. The second adhesive force may be in the range of 5-15 gf. Inanother example, the second adhesive force may be in the range of 7-12gf. In yet another example, the second adhesive force may be about 10gf.

In step, 304 a plurality of pads are bonded to a second surface of thefirst liner, using a second adhesive. The second adhesive can beconfigured to provide a bond strength (e.g., of a third adhesive force)between the pads and the second surface of the first liner that is lessthan the first adhesive force.

As discussed above, the pads may be foam or another material that blocksUV light. As such, the pads help to maintain a bond between the cellsand the first surface of the first liner by preventing degradation ofthe first adhesive caused by UV exposure.

Additionally, each pad can correspond with a battery cell that is bondedto an opposite side of the first liner. As discussed above, thethickness of each individual pad can correspond with a thickness of theassociated battery cell such that thicker battery cells are paired withthinner pads, and thinner (or shorter) battery cells are paired withthicker (or taller) pads. In some aspects, a total height for a givenbattery cell/pad pair is equal across all cell/pad pairings in thebattery pack.

FIG. 4 illustrates a portable electronic device 400, including a batterypack 406, in accordance with various aspects of the describedtechnology. Battery pack 406 can generally be used in any type ofelectronic device. For example, FIG. 4 illustrates a portable electronicdevice 400 that includes a processor 402, a memory 404 and a display408, which are all powered by battery pack 406.

Electronic device 400 can correspond to a laptop computer, tabletcomputer, mobile phone, personal digital assistant (PDA), digital musicplayer, watch, wearable device, and/or other type of battery-poweredelectronic device. Battery 406 may correspond to a battery pack thatincludes one or more battery cells, such as first and second prismaticcells, as discussed above.

Although a variety of examples and other information was used to explainaspects within the scope of the appended claims, no limitation of theclaims should be implied based on particular features or arrangements insuch examples, as one of ordinary skill would be able to use theseexamples to derive a wide variety of implementations. Further andalthough some subject matter may have been described in languagespecific to examples of structural features and/or method steps, it isto be understood that the subject matter defined in the appended claimsis not necessarily limited to these described features or acts. Forexample, such functionality can be distributed differently or performedin components other than those identified herein. Rather, the describedfeatures and steps are disclosed as examples of components of systemsand methods within the scope of the appended claims.

It is understood that any specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged, or that only aportion of the illustrated steps be performed. Some of the steps may beperformed simultaneously. For example, in certain circumstances,multitasking and parallel processing may be advantageous. Moreover, theseparation of various system components in the embodiments describedabove should not be understood as requiring such separation in allembodiments, and it should be understood that the described programcomponents and systems can generally be integrated together in a singlesoftware product or packaged into multiple software products.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.”

A phrase such as an “aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations. Aphrase such as an aspect may refer to one or more aspects and viceversa. A phrase such as a “configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A phrase such as a configuration mayrefer to one or more configurations and vice versa.

The word “exemplary” is used herein to mean “serving as an example orillustration.” Any aspect or design described herein as “exemplary” isnot necessarily to be construed as preferred or advantageous over otheraspects or designs.

What is claimed is:
 1. A battery pack comprising: a plurality of batterycells, wherein each of the battery cells are bonded to a first surfaceof a first liner via a first adhesive, wherein the first adhesive isconfigured to provide a first adhesive force between each of the batterycells and the first surface of the first liner; and a plurality of pads,wherein each of the pads is bonded to a second surface of the firstliner via a second adhesive, wherein the second adhesive is configuredto provide a second adhesive force between each of the pads and thesecond surface of the first liner, and wherein the second adhesive forceis less than the first adhesive force, wherein the first adhesive forceis configured to be reduced after exposure to ultraviolet (UV) light toa third adhesive force, wherein the third adhesive force is less thanthe first adhesive force.
 2. The battery pack of claim 1, wherein eachpad of the plurality of pads is coupled to a second liner.
 3. Thebattery pack of claim 2, wherein the second liner blocks UV light. 4.The battery pack of claim 1, wherein each pad of the plurality of padsblocks UV light from reaching the first adhesive.
 5. The battery pack ofclaim 1, wherein at least two pads of the plurality of pads have adifferent thickness.
 6. The battery pack of claim 1, wherein at leasttwo batteries of the plurality of battery cells have a differentthickness.
 7. The battery pack of claim 1, wherein the first liner istranslucent to UV light.
 8. The battery pack of claim 1, wherein thefirst liner is transparent to UV light.
 9. A method of manufacturing abattery pack, the method comprising: bonding a plurality of batterycells to a first surface of a first liner using a first adhesive,wherein the first adhesive is configured to provide a first adhesiveforce between each of the battery cells and the first surface of thefirst liner; bonding a plurality of pads to a second surface of thefirst liner using a second adhesive, wherein the second adhesive isconfigured to provide a second adhesive force between each of the padsand the second surface of the first liner, and wherein the secondadhesive force is less than the first adhesive force, wherein the firstadhesive force is configured to be reduced after exposure to ultraviolet(UV) light to a third adhesive force, wherein the third adhesive forceis less than the first adhesive force.
 10. The method of claim 9,wherein each pad of the plurality of pads is coupled to a second liner.11. The method of claim 9, wherein at least two pads of the plurality ofpads have a different thickness.
 12. The method of claim 9, wherein atleast two batteries of the plurality of battery cells have a differentthickness.
 13. A method for installing a battery pack, the methodcomprising: disposing a battery pack within a chassis of an electronicdevice; wherein the battery pack comprises a plurality of battery cellsbonded to a first liner using a first adhesive providing a firstadhesive force, wherein a plurality of pads are bonded to a secondsurface of the first liner using a second adhesive providing a secondadhesive force, and wherein the plurality of pads are bonded on anopposite side to a second liner, wherein the second adhesive force isless than the first adhesive force; stripping away the second liner andthe plurality of pads from the first liner to expose the first liner;and exposing the first adhesive to ultraviolet (UV) light to reduce thefirst adhesive force to a third adhesive force, wherein the thirdadhesive force is less than the first adhesive force.
 14. The method ofclaim 13, further comprising stripping away the first liner from theplurality of battery cells to install the battery cells within theelectronic device.
 15. The method of claim 13, wherein the firstadhesive force is between 50-100 gf (gram force).
 16. The method ofclaim 13, wherein the third adhesive force is between 5-15 gf (gramforce).
 17. The method of claim 13, wherein at least two pads of theplurality of pads have a different thickness.